CHAPTER IV. 



the play of animals (continued). 



Love Plays. 



The treatment of this class of plays in a separate 

 chapter is justified not only on the ground of its impor- 

 tance to animal psychology, but also for two reasons 

 inherent in its nature. The first of these reasons is that 

 it embraces the vexed question of sexual selection, and 

 the second reason is that this kind of play differs from 

 all that we have previously considered in being, strictly 

 speaking, not mere practice preparatory to the exercise 

 of an instinct, but rather its actual working. Yet it is 

 universally spoken of as play, and consequently our first 

 question is, How far is this designation correct? 



In considering it we are at once brought face to 

 face with the problem of sexual selection, for Darwin 

 regards all phenomena connected with love play as the 

 direct result of the operations of this, his second great 

 principle of evolution. Sexual selection, then, involves 

 two distinct phenomena: on the one hand the conflict 

 between males for the possession of a female, and on 

 the other hand the preference of the latter for certain 

 qualities or capacities in the former. Each of these 

 phenomena is supposed to produce its own effect in the 

 modification of characters. The first, being only a 



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